Production And Utilization Of Porous Hollow Epoxy By Water-Based Method As An Advanced Filler
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Date
2009-12
Authors
Du Ngoc, Uy Lan
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Porous hollow epoxy - PHE was produced by water based method and used as
filler in polymer in order to improve the “collaborative properties” of filler in
composites. The PHE was produced by allowing the incomplete coalescence of epoxy
tiny droplets in emulsion, which was prepared by homogenizing the mixture of
epoxy, polyamide and calcium carbonate in water medium. These epoxy particles
after cured are porous, hollow and spherical. The holes on epoxy particle could be
filled by the polymer matrix to form interlocking between epoxy particle and
polymer. The interlocking should be promising better interaction and has potential to
be used as reinforcing fillers. This interlocking mechanism is a new and novel
concept.
To prepare composites, the polymer used as matrix were chosen in three
types: elastomers: NR latex, NR and ENR; thermoset: epoxy cured polyamine;
thermoplastic: LLDPE, PS and PMMA. The results showed the interlocking was
obtained for all of the used polymer matrix. The mechanical properties were
maintained or enhanced depending on the used polymer. Different polymer would
result in different failure modes of the interlocking. In general, there are three
proposed failure modes, which were classified as pulling out (maintain interlocked
morphology and deform interlocked morphology), matrix broken at interlocking
neck, and PHE broken. The interlocking was also effect thermal properties of
composites. Composite could endure better heat since epoxy is a good heat resistance
material due to its three dimension crosslink networks. PHE could affect to polymer
chain mobility resulting in slight reduction of glass transition temperature of
thermoplastic (LLDPE, PS and PMMA).
In-situ polymerization was carried out to investigate the effect of PHE on
suspension of styrene/methyl methacrylate (MMA) as well as sol-gel process. The
interlocking through epoxy holes between PHE and PS/PMMA was successfully
obtained as SEM photo of cutting surface pPS-PHE and pPMMA-PHE beads. PHE
had found to react with BPO and retard the polymerization of styrene and MMA.
Moreover, the effect of PHE had found on polymerization of MMA reflecting on
different molecular weight obtained at inner and outer epoxy hole’s. However, the
effect could not be apparent for styrene polymerization due to its non polarity. For
sol-gel process, TGA results exhibited a similar portion of silica remained of non
PHE and interlocked PHE samples, so it could be said that PHE could have very low
effect to sol-gel process.
The effect of particle size and hole’s morphology of PHE on suspension
polymerization of MMA and melt blending with PMMA was investigated. The use of
smaller PHE resulted in higher molecular weight of PMMA obtained. However,
thermal properties did not show an obvious difference. For PMMA melt blending
composites, it is interesting that larger PHE particle expressed slightly higher tensile
properties. There are three types of PHE in the size of 38 – 53 μm, and 53 – 75 μm
with less holes, and 75 – 106 μm with multiple holes. It could be said that they are
small particle with less medium holes, medium particle with medium holes, and large
particle with many small holes. The optimum reinforcement particle is 53 – 75 μm. It
concluded that a PHE with optimum number of holes and optimum hole’s size would
be a good reinforced filler, which improved better all tensile properties such of tensile
strength, elongation as well as modulus
Description
Keywords
Production And Utilization Of Porous Hollow Epoxy , Water-Based Method As An Advanced Filler